Identification Key for Organizational Units 
Identification Key for Organizational Units
Definition
An organizational unit (OU) is defined by means of a unique identification key.
Use
The identification key of the OU can be assigned by the system (internal number assignment), or you can assign it yourself (external number assignment). In Customizing for IS-H, you can specify whether one of these two number assignment methods should be excluded.. In Customizing, you can also define the number ranges authorized for internal and external number assignment.
If you assign external identification keys, it is possible to use mnemonic keys (e.g. unit07 for care unit 7). Note, however, that once assigned, the identification key of an OU cannot be changed. For instance, should your hospital be restructured, the mnemonic keys of the OUs may no longer match the new structure. You should therefore avoid using mnemonic keys.
The OU identification keys must be unique within a client. The system ensures that unique identification keys are always assigned. When internal number assignment is used, the system selects the next number from the internal number range in each case. When external number assignment is used, the system prevents a number that has already been used from being assigned again.
If you have defined several institutions in one client and are using external number assignment, you can specify a prefix for each institution which the system places at the start of the identification key of the institutions. This enables you to designate the organizational units which belong to the organizational structure of an institution.